The present invention relates to a motorized manipulator.
Numerous articulated motorized manipulators are already known and they are generally used on the basis of a support and are either suspended on a mobile overhead crane or are carried by a vehicle supported on the ground, in this way becoming autonomous.
In general, these manipulations comprise two articulated segments carrying at their end tongs or more generally a tool. These two segments are generally called the "arm" and the "forearm" respectively. The assembly has 6.degree. of freedom permitting the position and orientation of an object held by the tongs in all positions and orientations within the limits of the manipulator displacement possibilities. To this end in the case of such manipulators, there is generally a rotation of the forearm about its own axis and the joint of the wrist, i.e. the joint between the forearm and the tool provides the two complimentary rotations. These three rotation movements essentially constitute the degrees of freedom of orientation of the tool, whilst the movements of the elbow, i.e. about the joint between the arm and the forearm, the movement of the shoulder, i.e. between the arm and the support and the rotation movement of the whole manipulator generally constitute the degrees of freedom of position. This arrangement has the disadvantage of opposing the advance of the tool when it is a question of placing the wrist carrying the tool in areas having large obstacles. Thus, in order that the degrees of freedom of orientation are linked to only a limited extent with the degrees of freedom in position the last arm of the lever, under the circumstances, the lever arm of the tongs, must have a limited length compared with the length of the previous segments constituting the arm and the forearm. As a result, the long segment constituted by the forearm limits the approach of the tongs or tool in obstructed areas. Thus, to a certain extent, these obstacles constitute shadow areas which cannot be entered by the tool.
Moreover, the manipulators can be subject to the action of a control using a computer and permitting the solution by cartesian coordinates of the positions of the manipulator according to its own degrees of freedom and conversely the solution of the cartesian coordinates of the tongs. This leads to a complex calculation necessitating the inversion of several matrixes because there is a connection between the orientation movements of the tongs or the tool and the position movements of the manipulator. Thus, even in the standard arrangement where the articulation axis of the wrist is offset with respect to the forearm axis, the change of coordinates is particularly complex and requires a calculation by iterations effected by the computer.
The manipulator according to the invention makes it possible to isolate the orientation movements from the position movements, which considerably simplifies its control by computer.
Finally, numerous manipulators are known, which are generally used industrially and rest directly on the ground by their stand. The manipulator according to the invention makes it possible to obtain the support on the ground with a significant mobility, which greatly increases its intervention area, whereby the manipulator becomes autonomous and has a much greater field of action.